摘要
采用更新式静态急性试验法,研究了灭多威和辛硫磷对罗非鱼的单一及联合毒性。结果显示,灭多威和辛硫磷对罗非鱼的24、48、96 h-LC50分别为1.25、0.75、0.43 mg·L-1和13.30、6.98、4.58 mg·L-1,安全浓度分别为0.043 mg·L-1和0.458 mg·L-1。按照农药毒性分级标准,灭多威对罗非鱼是极高毒农药,辛硫磷对罗非鱼是高毒农药。联合毒性试验结果显示:灭多威和辛硫磷在24、48、96h的相加指数分别为0.24、0.26、0.06,相加指数均大于零;SOD活性研究显示,灭多威、辛硫磷以及灭多威+辛硫磷对SOD活性有显著抑制效应,且抑制作用随染毒浓度的增加而增强,同时,灭多威和辛硫磷联合染毒对罗非鱼肝脏SOD活性的抑制效应较相同条件下单一灭多威或辛硫磷染毒时强;表明灭多威和辛硫磷对罗非鱼的联合毒性表现为协同作用,它们的共存会对鱼类产生更强的毒性作用。在环境评价中,决不能简单地将各单一污染物毒性相加来判断其综合毒性。
Methomyl and phoxim,widely used to control pest insects both in China and in the world,enter water bodies directly or indirectly,causing toxicity to fishes in aquatic ecosystems.An experiment was carried out to examine the single and joint toxicities of methomyl and phoxim to tilapia(Oreochromis niloticus).The 24 h,48 h,and 96 h-LC50of methomyl and phoxim to tilapia were 1.25,0.75 mg·L-1,and0.43 mg·L-1and 13.30,6.98 mg·L-1,and 4.58 mg·L-1respectively.Their safe concentrations to tilapia were 0.043 mg·L-1for methomyl and0.458 mg·L-1for phoxim,implying high toxicity of methomyl and phoxim to tilapia.Additive indexes of both pesticides were 0.24,0.26 and0.06 at 24 h,48 h and 96 h respectively.The activity of hepatic SOD was inhibited by methomyl and phoxim alone and in combination,with inhibitory effects being increased with pollutant concentrations.The joint effects of methomyl and phoxim were greater than their respective single.It is concluded that co-extistence of methomyl and phoxim in environemnt has greater toxicity to aquatic lives.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2014年第2期257-263,共7页
Journal of Agro-Environment Science
基金
中国水产科学研究院级基本科研业务费项目(2013A0303)
现代农业产业技术体系建设专项资金(CARS-49)
